Exam 1 Flashcards
Ecology
The study of the interactions between organisms and their environment
Organism
The unit of natural selection; an individual existing within an ecosystem
Population
The unit of evolution; Organisms of the same species living together in a specific area
Community
The level above population; an assemblage of populations of different species, interacting with one another
Ecosystem
The interacting parts of the biological and physical worlds
Biosphere
The planet Earth; the collection of all of our planet’s ecosystems
Levels of Complexity
Organism
Population
Community
Ecosystem
Biosphere
How is science a “subjective” process?
Our experiences and perspectives influence the “truth” that we approximate through our use of tools and measurements, leading to subjectivity.
Therefore, “good” science can minimize bias by incorporating multiple perspectives and collaborators
Ernst Haeckel
German biologist and philosopher who coined the term “oikologie” from the greek word oikos = home
Ellen Swallow Richards
An MIT Chemist who was the one to really launch the field of ecology by studying human impact on water chemistry.
Stood up at a conference and told everyone to stand witness to the birth of the field of oikologie.
What is the difference between basic and applied ecology?
Basic: Gathering knowledge for knowledge’s sake
Applied: Driven by a human need (Ex: invasive species)
What are the three ways to organize or think about ecology and how are they studied?
Taxanomic Organization: Makes it easy for ecologists to compare/study
Organization by place or function: studying organism’s niches
Organization by location: studying the habitats in which organisms live
What are the three different types of studies that ecologists use to conduct science?
- Observational Studies: More realism/applicability
- Models: Conceptual and Mathematical - can illustrate relationships best
- Experiments: Field and Microcosm/Mesocosm - most control over variables, micro/meso has most replication
How do you calculate the variance of a sample?
Divide the sum of squares by the degrees of freedom.
v = [Σ(xi - µ)2] / (n-1)
Taxonomy
The classification of organisms by their unique characteristics into species.
Habitat
The place or physical settings in which an organism lives
Niche
The range of conditions an organism can tolerate and the way of life it pursues
Scientific Method
What properties of water make it beneficial for life?
It is dense and viscous
Stays liquid over broad range of temperatures
Unique densities at various temperatures
Good solvent
What aspects of water affect habitat types?
Availability
Salinity
Temperature
Flow speed
What three materials make up the different types of soils and how does their composition affect the soil?
Soil is made up of differing proportions of:
Sand
Silt
Clay
Their differing proportions change soil’s ability to
Hold water
Describe the seasonal process of mixing in temperate lakes.
Summer: Lake stratified, warmest at top, coldest at bottom. 28-8-4
Fall: Mixing, even temperature throughout. 4-4-4
Winter: Ice cover - density curve makes warmer at bottom. 0-3-4
Spring: Mixing again, even temp throughout. 4-4-4
How do freshwater fish deal with osmotic gradients?
Freshwater causes freshwater fish to lose salts and gain water.
They counter this by excreting excess water via urine, kidneys retain ions in blood, and absorbing salts/ions in their gills.
How do marine fish deal with osmotic gradients?
Saltwater causes marine fish to lose water and have excess solutes.
They counter this by increasing solute excretion through gills and kidneys, while drinking excess water.
How do plants get water from their roots to the tips of their shoots?
Intake at roots via osmosis
Transport up xylem via cohesion-tension
Exit through stomate via transpiration, which maintains the tension/negative pressure
What is the PAR?
Photosynthetically Active Region
Refers to visible light, or the wavelengths at which plant molecules absorb light to perform photosynthesis.
Albedo
Reflectivity of an ecosystem
Higher albedo = more reflection
Snow is highest, dense forest low
Describe the Algific Talus slopes in “the Driftless Region” and what makes them noteworthy.
The Northern Monkshood flower and the Iowa Pleistocene Snail persist in this area that was not covered in glaciers.
Winter air is drawn into vents to turn water into ice and blown out the top.
Summer air blows across underground ice/cold water and brought to the slope vents like air conditioning.
What is a “life history tradeoff” and what are some examples?
An adaptation that gives an organism some sort of advantage in its habitat, but requires energy and comes at the cost of being able to do something else well.
Examples:
- C4 Photosynthesis (can close stomates due to CO2 transport to bundle-sheath cells),
- CAM Photosynthesis (stomates open during night, closed during day bc of dry climates)
- Homeothermy (less dependent on enviro for temp mgmt, but takes energy)
Which wavelengths of light are able to travel longer distances in water? What does this mean for adaptations that plants at shallower vs deeper depths might have?
Blue/Short. This means that plants at shallower depths will absorb more red/long wavelength light than plants at deeper depths, which will thrive on blue/short wavelength light.
What are the three types of heat transfer?
Radiation: emission of electromagentic energy by a warm surface
Conduction: transfer of heat energy via contact
Convection: transfer of heat energy by movement of liquids or gases
Supratidal Zone
AKA Splash zone; the area above the highest tide that is never submerged, but is often splashed by waves
Neritic System
The system of zones that extend to depths out to the beginning of the continental shelf.
Supratidal
Intertidal
Subtidal
Oceanic System
The zones that occur beyond the continental shelf.
Bathyal
Abyssal
Hadal/benthic
Benthic Zone
The lowest depths of an ocean or lake
Pelagic Zone
Open water zones that are not near the bottom, whether in an ocean or lake.
Photic Zone
Portion of a body of water that receives sunlight.
Aphotic Zone
Portion of a body of water that does not receive sunlight
Littoral Zone
The shallows; portion of an ocean that is not past the continental shelf.
Limnetic Zone
Portion of a body of water that is out in the open water or past the continental shelf
Homeotherm
An organism that uses energy to maintain a constant body temperature
Poikilotherm
An organism that allows its internal body temperature to change with the environmental temperature
C3 Photosynthesis
The most common method of photosynthesis
Uses RUBP (Rubisco, low CO2 affinity) to make a 3-C compound in mesophyll cell.
Must have its stomates open a lot, risking dessication
C4 Photosynthesis
Use PEP Carboxylase to make a 4-C compound that is shuttled into bundle sheath cells and converted to the normal 3-C compound.
Allows plant to close stomates more often to protect from dessication.
Crassulacean Acid Metabolism (CAM) Photosynthesis
Discovered by Edith Bellamy Shreve
Same as C4, but only open stomates during night to protect further from dessication.
Best adapted to dry environments.
Edith Bellamy Shreve
Discovered CAM Photosynthesis plants in arid conditions.
Jim Brown
U. New Mexico, proposed the Metabolic theory of ecology, which states that as temperature increases, maximum growth rate decreases
Lauren Buckley
Using bioenergetic modeling, she has applied global climate change maps to effects seen in the energy management of organisms themselves
C. Hart Merriam
Developed the idea of “Life Zones” at different elevations that have distinct vegetation and water availability differences
What abiotic factors can limit species distributions?
Precipitation
Temperature
Nutrient Availability
Light
What is the primary cause of global patterns in climate and vegetation?
Differences in solar radiation across latitudes and Hadley Cells
Hadley Cells
Up at the equator, out to 30° lat, down to make deserts
What abiotic factors cause regional differences in climate and vegetation?
Rain Shadow Effect
Slope and Aspect
Elevation
Soil composition
Etc.
What abiotic factors influence species distribution in water?
Light
Water Flow
Salinity
Temperature
Nutrients
What is the River Continuum Concept?
It describes the differences between streams of different widths (order 1 is narrow - order 12 is very wide)
Higher order streams have higher numbers of trophic levels
Lower order have allochthonous inputs
Higher orders have autochthonous inputs
Upwelling Zones
Water zones where the Coriolis Effect and prevailing winds act on the ocean to bring cool, nutrient-rich water up on the western coasts of continents during spring and summer.
They lead to very productive communities
Rain Shadow Effect
Moisture builds up as the prevailing winds blow towards a mountain, ending in precipitation on one side of the mountain, with dry wind dessicating the other side into a desert.
Adiabatic Cooling
Air cools as it rises in elevation and volume and decreases in pressure.
ENSO event
El Niño Southern Oscillation Event
4 yrs from El -> La -> El
Occur every 2-10 years
El Niño causes warm winter for USA
Charles Elton
An ENGLISH ecologist who linked organisms with physical factors
Also coined the term food web
Food Web
Feeding relationships among interconnected organisms
A.G. Tansley
An ENGLISH scientist who coined the term ecosystem
Alfred J. Lotka
An AMERICAN scientist who linked energy transfer in an ecosystem to the 2nd Law of Thermodynamics
Raymond Lindeman
An AMERICAN scientist who studied uner G.E. Hutchinson and used equations to define/quantify energy in trophic levels as well as how much passes between them.
Eleanor Hall Lindeman
Wife of Raymond Lineman, who died at age 27. She helped him complete his graduate studies, often hauling samples into their boat while he was vomiting over the side.
Raymond’s PhD dissertation was rejected by journals, but resubmitted by G.E. Hutchinson and accepted.
Eugene P. Odum
Furthered work on quantifying ecosystem ecology. Created the “Universal Model”:
Boxes at any trophic level can show inputs, assimilation, and outputs to other trophic levels, etc.
What are three ways by which production can be quantified?
Measuring Biomass
Measuring Carbon isotopes
Measuring Photosynthetic rates
What abiotic factors limit production?
Precipitation
Light
Temperature
Nutrients
How do the flux pyramids differ for energy and biomass?
Energy flux pyramids always taper UP
Biomass pyramids can taper in EITHER direction
Production
Energy within an ecosystem
Ecological Efficiency Equation
NPPn/(n-1) * 100%
The % of energy transferred from one level to the next
Food Web
Feeding relationships among interconnected organisms
Gross Primary Production (GPP)
The energy that is assimilated and respired
Net Primary Production (NPP)
Only the energy that is assimilated
Trophic structure
the organization of energy levels and the way producers/consumers
What are the two ways which organisms can disperse?
Spatially and temporally (dormancy, hibernation)
How does chili peppers’ hotness help them disperse?
Since birds are immune to capsacin, they become perfect high-quality dispersers for chili seeds.
Mammals and walkers are not immune to the hotness of capsacin, so they are selected against.
What are the differences between movement, dispersal, and migration?
Movement: Org changes physical position/location
Dispersal: Movement away from place of birth
Migration: Seasonal movement of a complete population
What are some COSTS and BENEFITS of movement, dispersal, and migration?
Costs: takes lots of energy to move
Less chance to mate
susceptible to predation in new environment
BENEFITS: can escape poor conditions, find new resources
Long-Distance Dispersal (LDD)
Unusually long movements when dispersing from one place to another
Walter Diagrams
Describe biomes using temperature, precipitation, and months of the year when the min Temp is above 0
Whittaker Diagrams
describe biomes by ascribing environmental variables to vegetation patterns including Temperature, precipitation, and disturbance by fire
Tropical Rain Forest
Location, Climate Zone, Vetetation
Loc: Equatorial
CZ: Always moist and year-round mild temps
Veg: Evergreen tropical rain forest
Tropical Seasonal Forest/Savanna
Location, Climate Zone, Vetetation
Loc: Tropical
CZ: Summer rainy and winter dry season
Veg: Seasonal forest, scrub, or savanna
Subtropical Desert
Location, Climate Zone, Vetetation
Loc: Subtropical (hot deserts)
CZ: Highly seasonal, arid climate
Veg: Desert vegetation with considerable exposed surface
Woodland/Shrubland
Location, Climate Zone, Vetetation
Loc: Mediterranean
CZ: Winter rainy season and summer drought
Veg: Sclerophyllous (drought-adapted), frost-sensitive shrublands and woodlands
Temperate Rain Forest
Location, Climate Zone, Vetetation
Loc: Warm temperate
CZ: Occasional Frost, often with summer rainfall maximum
Veg: Temperate evergreen forest, somewhat frost-sensitive
Temperate Seasonal Forest
Location, Climate Zone, Vetetation
Loc: Nemoral
CZ: Moderate climate with winter freezing
Veg: Frost-resistant, deciduous, temperate forest
Temperate Grassland/Desert
Location, Climate Zone, Vetetation
Loc: Continental (Cold deserts)
CZ: Arid, with warm or hot summers and cold winters
Veg: Grasslands and temperate deserts
Boreal Forest
Location, Climate Zone, Vetetation
Loc: Boreal
CZ: cold temperate with cool summers and long winters
Veg: Evergreen, frost-hardy needle-leaved forest (taiga)
Tundra
Location, Climate Zone, Vetetation
Loc: Polar
CZ: Very short, cool summers and long, very cold winters
Veg: Low, evergreen vegetation, without trees, growing over permanently frozen soils
Large River Deltas
Nutrient rich, biodiverse, 12 on continuum
Low flow
Many trophic levels
Temperate Upland rivers
5-6 trophic levels (intermediate)
Endemism
Moderate Flow
Large Lakes
Biodiverse
Both Temperate and tropical regions
Endemism
Polar Seas
Low temps and salinity
Lots of plankton when whales absent bc of high DO
Upwelling brings nutrients
Temperate Shelfs and Seas
Some stratification
Tide influence bc near coasts
Relatively shallow -> warm
Tropical Coral
HYPER diverse
shallower water -> warm, lots of light
Temperate Upwelling Zones
High nutrients, biodiversity, and endemism
Lower than expected temps
W Coasts only!
Structurally complex and fragile
Tropical Upwelling Zones
Similar to Temperate (high nuts, biodiversity, and endemism)
VERY diverse bc warmer by default
structurally complex and fragile
How long are Earth’s natural heating and cooling cycles?
100,000 yr long cycles
10,000 yrs of cooling
90,000 yrs of warming
The Carbon Cycle
Water Cycle
What are the 3 major greenhouse gases?
CO2, CH4, and N20
Milankovitch Cycles
Changes in Earth’s heating and cooling based on changes in the Earth’s tilt
Free Air Carbon Dioxide Enrichment (FACE)
An experiment where scientists enrich the air around plants with CO2 and see how growth changes.
The Nitrogen Cycle (Simplified)
What are the Inputs and Losses of Phosphorus in an ecosystem?
INPUTS: Weathering, Wind deposition, and Humans
Losses: Organism Uptake and Particulate Erosion
What is a dead zone and what causes them?
It is a portion of habitat that has changed so much over a short period of time that the organisms that live there cannot survive.
Especially caused by excesses of nutrients.
Nitrification
NH3/NH4+ -> NO3-
Denitrification
NO3- -> N2
Ammonification
N2 -> NH3/NH4+
What are some examples of non-symbiotic nitrogen fixation?
Lightning
Cyanobacteria
What are the effects of eutrophication on an ecosystem?
Lower diversity
Higher production
Shifts in spp composition
Higher consumer abundance (but lower diversity)
Lincoln-Peterson Index
AKA mark-recapture equation
Marked in 2nd sample / #caught in 2nd sample
=
caught in 1st sample / total pop size
What does the Lincoln-Peterson Index assume?
All indivs =ly likely to be captured
N doesnt change betw sampling
No marked indivs are lost
What is the simplest form of population growth?
EXPONENTIAL (can be continuous or discrete)
Assumptions of Exponential Growth Model
All individuals are same age and genetics
B and D are constant
No E or I
Habitat is perfectly uniform
What is the difference between exponential and geometric growth?
None really; one is continuous and one is discrete.
What does the Logistic Growth Model represent?
Who was it “created” by?
Density-Dependent Growth
Lowell Reed and Raymond Pearl
Fecundity
bx
The # of FEMALE offspring produced per reproductive season or age interval
Survival
Sx
Probability of surviving to the next age class
S = nx+1/nx
Survivorship
lx
Probability of a newborn surviving to age x
Divide population at age x by initial population size
lx = nx/no
Net Reproductive Rate (Ro)
Mean # of offspring that a female produces in her lifetime
=Σbxlx
Generation Time (T)
Avg age of parents of all offspring produced by a single cohort
AKA how long it takes to breed a new generation
T = Σxbxlx/Σbxlx
=Σbxlx/Ro
What is the difference between positive and negative density dependence?
Positive: growth increases with density (more mates, yay!)
Negative: Crowding
Allee Effect
Population growth is positively density-dependent until resources start becoming scarce
This is when the INFLECTION point happens
Ideal Free Distribution
Organisms in a habitat will distribute to various patches of resources.
The patch with the highest number of resources will have the highest number of individuals.
